If you don't have a great header in the middle you render Costa useless on the left. He's too predictable cause he can't cut in. Will run all the way to the corner flag and cross. Rinse and repeat.
If you play him on the right, he can cut in AND chip crosses behind the defense. Overall He's not as predictable on the right and arguable harder to stop as well.
With that in mind, Higgy is our to go striker, not too famous for his headers, so it makes more sense for us to play Costa on the right, where he can do much more on his own than on the left.
Would we play Mandzu as ST, i'd look different, since Costa would have a great header to cross to, but we don't. So better leave him on the right.